A rail gun consists of two parallel metal rails (hence the name) connected to an electrical power supply and placed within an independent magnetic field perpendicular to the plane in which the rails lay. When a conductive projectile or sled is injected between the rails, an electric current flows through the projectile or sled, between the rails and through the magnetic field. This current flowing through the magnetic field sets up a Lorentz force driving the projectile or sled down the rails.
A capacitive stator is a device which couples electromagnetic energy with matter inducing momentum from a distance. The capacitive stator induces momentum to either charged and/or uncharged gasses (i.e., ionized or non-ionized), liquids, and/or solids. For the charged case, energy coupling is mechanized via the Lorentz force. For the uncharged case, energy coupling is mechanized via diamagnetism.